Question

拜托哪位好心帮我把这段给翻译成英语，小弟感激不尽。

为了保持3G在十年内的竞争力，3GPP组织在2004年底通过了3G长期演进计划（Long Term Evolution，简称LTE）。LTE旨在提高数据传输速率，降低系统时延，降低系统时延，增大系统容量和覆盖范围，同时降低运营成本。OFDMA（Orthogonal Frequency Division Multiple Access）作为LTE下行无线接入的技术，具有抗多径衰落、频谱效率高的优点。但是OFDMA的一个主要的缺点就是一个OFDM符号上的瞬时发射功率的变化非常大，这样会导致非常高的峰均比（PAPR—Peak to Average Power Ratio）。在LTE上行链路中高峰均比是一个非常严重的问题，因为手机的发射功率是上行需要考虑的主要问题。与OFDMA相比，SC-FDMA（Single Carrier Frequency Division Multiple Access）具有单载波的低PAPR和多载波的强韧性的两大优势。因此，LTE上行多址访问技术采用了SC-FDMA。
本文基于SC-FDMA系统，与3GPP LTE所规定采用的集中式子载波映射方式相结合，着重研究动态频域资源分配方案的性能，即动态子载波分配。首先，介绍了LTE物理层的技术方案，并重点阐述了本文所采用的SC-FDMA传输方案的标准及相关演进过程。其次，介绍了动态子载波分配的基本原理与特性。之后，分别介绍了贪婪分配算法（greedy algorithm），比例公平算法（proportional fair algorithm）以及应用于传统固定式子载波分配的轮循算法（Round robin algorithm）。最后，在信道容量、分配公平性以及计算复杂度三方面比较这三种算法应用于动态子载波分配的性能差异，给出MATLAB仿真分析，说明动态资源分配的特性、优势以及不足。

Answer 1

3G in order to maintain competitiveness in a decade, 3GPP organization by the end of 2004 the 3G Long Term Evolution Plan (Long Term Evolution, referred to as LTE). LTE aims to improve data transfer rates, reduce system latency, reducing system latency and increase system capacity and coverage, while reducing operating costs. OFDMA (Orthogonal Frequency Division Multiple Access) as the LTE downlink radio access technology, has anti-multipath fading, the advantages of high spectrum efficiency. But a major drawback OFDMA is an OFDM symbol on the changes in the instantaneous transmission power is very large, it will lead to a very high PAPR (PAPR-Peak to Average Power Ratio). The uplink in LTE than the peak is a very serious problem, because the phone is the uplink transmission power of the main issues to be considered. Compared with OFDMA, SC-FDMA (Single Carrier Frequency Division Multiple Access) with a single carrier and multicarrier PAPR low strength and toughness of the two major advantages. Therefore, LTE uplink multiple access technology uses a SC-FDMA.
Based on the SC-FDMA system, and used under the 3GPP LTE carrier mapping concentrated formula combines focuses on the dynamic resource allocation scheme for frequency-domain performance, that is, dynamic subcarrier allocation. First of all, introduces the LTE physical layer technology solutions, and focuses on the paper used the SC-FDMA transmission scheme of the evolution of standards and related processes. Secondly, the introduction of dynamic subcarrier allocation in the basic principles and characteristics. After the introduction of the greedy allocation algorithm, respectively (greedy algorithm), proportional fair algorithm (proportional fair algorithm) and the formulas used in traditional fixed carrier allocation round robin algorithm (Round robin algorithm). Finally, channel capacity, distributive justice and the three aspects of computational complexity comparison of these three dynamic subcarrier allocation algorithm is applied to the difference in performance, given MATLAB simulation analysis shows that dynamic resource allocation features, advantages and disadvantages.

Answer 2

英语是： 3G in order to maintain competitiveness in a decade, 3GPP organization by the end of 2004 the 3G Long Term Evolution Plan (Long Term Evolution, referred to as LTE). LTE aims to improve data transfer rates, reduce system latency, reducing system latency and increase system capacity and coverage, while reducing operating costs. OFDMA (Orthogonal Frequency Division Multiple Access) as the LTE downlink radio access technology, has anti-multipath fading, the advantages of high spectrum efficiency. But a major drawback OFDMA is an OFDM symbol on the changes in the instantaneous transmission power is very large, it will lead to a very high PAPR (PAPR-Peak to Average Power Ratio). The uplink in LTE than the peak is a very serious problem, because the phone is the uplink transmission power of the main issues to be considered. Compared with OFDMA, SC-FDMA (Single Carrier Frequency Division Multiple Access) with a single carrier and multicarrier PAPR low strength and toughness of the two major advantages. Therefore, LTE uplink multiple access technology uses a SC-FDMA.
Based on the SC-FDMA system, and used under the 3GPP LTE carrier mapping concentrated formula combines focuses on the dynamic resource allocation scheme for frequency-domain performance, that is, dynamic subcarrier allocation. First of all, introduces the LTE physical layer technology solutions, and focuses on the paper used the SC-FDMA transmission scheme of the evolution of standards and related processes. Secondly, the introduction of dynamic subcarrier allocation in the basic principles and characteristics. After the introduction of the greedy allocation algorithm, respectively (greedy algorithm), proportional fair algorithm (proportional fair algorithm) and the formulas used in traditional fixed carrier allocation round robin algorithm (Round robin algorithm). Finally, channel capacity, distributive justice and the three aspects of computational complexity comparison of these three dynamic subcarrier allocation algorithm is applied to the difference in performance, given MATLAB simulation analysis shows that dynamic resource allocation features, advantages and disadvantages.